1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
# Author: Alexandre Gramfort <alexandre.gramfort@telecom-paristech.fr>
#
# License: BSD (3-clause)
import os.path as op
import numpy as np
from numpy.testing import assert_array_almost_equal
from nose.tools import assert_true, assert_raises
import warnings
from mne.datasets import sample
from mne import read_label, read_forward_solution
from mne.time_frequency import morlet
from mne.simulation import generate_sparse_stc, generate_evoked
from mne import read_cov
from mne.io import Raw
from mne import pick_types_evoked, pick_types_forward, read_evokeds
warnings.simplefilter('always')
data_path = sample.data_path(download=False)
fwd_fname = op.join(data_path, 'MEG', 'sample',
'sample_audvis-meg-eeg-oct-6-fwd.fif')
raw_fname = op.join(op.dirname(__file__), '..', '..', 'io', 'tests',
'data', 'test_raw.fif')
ave_fname = op.join(op.dirname(__file__), '..', '..', 'io', 'tests',
'data', 'test-ave.fif')
cov_fname = op.join(op.dirname(__file__), '..', '..', 'io', 'tests',
'data', 'test-cov.fif')
@sample.requires_sample_data
def test_simulate_evoked():
""" Test simulation of evoked data """
raw = Raw(raw_fname)
fwd = read_forward_solution(fwd_fname, force_fixed=True)
fwd = pick_types_forward(fwd, meg=True, eeg=True, exclude=raw.info['bads'])
cov = read_cov(cov_fname)
label_names = ['Aud-lh', 'Aud-rh']
labels = [read_label(op.join(data_path, 'MEG', 'sample', 'labels',
'%s.label' % label)) for label in label_names]
evoked_template = read_evokeds(ave_fname, condition=0, baseline=None)
evoked_template = pick_types_evoked(evoked_template, meg=True, eeg=True,
exclude=raw.info['bads'])
snr = 6 # dB
tmin = -0.1
sfreq = 1000. # Hz
tstep = 1. / sfreq
n_samples = 600
times = np.linspace(tmin, tmin + n_samples * tstep, n_samples)
# Generate times series from 2 Morlet wavelets
stc_data = np.zeros((len(labels), len(times)))
Ws = morlet(sfreq, [3, 10], n_cycles=[1, 1.5])
stc_data[0][:len(Ws[0])] = np.real(Ws[0])
stc_data[1][:len(Ws[1])] = np.real(Ws[1])
stc_data *= 100 * 1e-9 # use nAm as unit
# time translation
stc_data[1] = np.roll(stc_data[1], 80)
stc = generate_sparse_stc(fwd['src'], labels, stc_data, tmin, tstep,
random_state=0)
# Generate noisy evoked data
iir_filter = [1, -0.9]
with warnings.catch_warnings(record=True):
warnings.simplefilter('always') # positive semidefinite warning
evoked = generate_evoked(fwd, stc, evoked_template, cov, snr,
tmin=0.0, tmax=0.2, iir_filter=iir_filter)
assert_array_almost_equal(evoked.times, stc.times)
assert_true(len(evoked.data) == len(fwd['sol']['data']))
# make a vertex that doesn't exist in fwd, should throw error
stc_bad = stc.copy()
mv = np.max(fwd['src'][0]['vertno'][fwd['src'][0]['inuse']])
stc_bad.vertno[0][0] = mv + 1
assert_raises(RuntimeError, generate_evoked, fwd, stc_bad,
evoked_template, cov, snr, tmin=0.0, tmax=0.2)
|
